Battle Partners

Throughout your journey in the Sinnoh region, you'll come across a few trainers who ask for your help to proceed through a variety of areas. These trainers will battle alongside you in multibattles and double battles against Wild Pokémon, while keeping your Pokémon healed during the segment. After you have done their segment, you will end up being able to battle them in Master Class in the Battle Tower

Cheryl

Location: Eterna Forest

When you first enter Eterna Forest, you will find the trainer Cheryl. She wants to go through the forest but is worried as there's a sinister group called Team Galactic around, so she requests you help her through the forest

Chansey
Pokémon Trainer Cheryl Chansey
Battle Type

Items
Level 15

Healer
Attacks:
Sweet Kiss
Disarming Voice
Tail Whip
Life Dew
Hold Item:
No Item
Nature:
Lax
Cheryl

Mira

Location: Wayward Cave

As you travel through Wayward Cave, when you reach the northeasternmost part, you will find the young girl, Mira. She will say she got lost in the cave and asks for your help to get out.

Kadabra
Pokémon Trainer Mira Kadabra
Battle Type

Items
Level 18

Synchronize
Attacks:
Kinesis
Psybeam
Reflect
Ally Switch
Hold Item:
No Item
Nature:
Lax
Mira

Riley

Location: Iron Island

When you go through Iron Island after defeating the Canalave City Gym, you'll find the trainer Riley. He will mention that the Pokémon in the area are acting unusually and thinks that if you two team up you'd be able to face any issue. At the end you'll find Team Galactic have been causing issues. Defeat them and your journey with Riley will end. He will give you a special Egg containing Riolu as thanks

Lucario
Pokémon Trainer Riley Lucario
Battle Type

Items
Level 34

Inner Focus
Attacks:
Screech
Force Palm
Metal Claw
Laser Focus
Hold Item:
No Item
Nature:
Serious
Riley

Marley

Location: Victory Road

After you have obtained the National Pokédex, you'll be able to go into the extra area of Victory Road towards Route 224. She will say that she wants to get to the end of the cave and asks for you to escort her. Get to the end and she'll mention the rock at the end of Route 224

Arcanine
Pokémon Trainer Marley Arcanine
Battle Type

Items
Level 57

Intimidate
Attacks:
Burn Up
Helping Hand
Leer
Howl
Hold Item:
No Item
Nature:
Serious
Marley

Buck

Location: Stark Mountain

After you get the National Dex and go to the Fight Area, you will meet Buck who says about a treasure that is to be found in Stark Mountain. When you go to Stark Mountain, he will mention how there's strong trainers in there and you'll do better if you team up together. At the end, he takes the Magma Stone found at the end back to the Survival Area

Claydol
Pokémon Trainer Buck Claydol
Battle Type

Items
Level 58

Levitate
Attacks:
Ancient Power
Cosmic Power
Extrasensory
Earth Power
Hold Item:
No Item
Nature:
Lax
Buck